The present invention generally relates to an electronic device that includes a means for calculating a non-linear equation of any type. For example, one use of the invention would be to calculate a person's body mass index (BMI), which may be determined based on the following equation: M/L2, where M is the body weight in kilograms, and L is the body height in meters. It is recognized that other equations may be used for calculating body mass index. For instance, the body weight may be expressed in pounds, and the body height by inches. Nonetheless, the present invention may be used as a calculating device to calculate the resultant number from a predetermined non-linear equation.
Numerous pens and other devices are available to determine the resultant figure from a simple linear equation, such as an ordinary mathematical multiplication table. In order to calculate a non-linear function, however, a logarithmic type of scale must be introduced, as well as a means for accessing the appropriate numerical values on both the logarithmic scale and the remaining factor(s) of the equation.
The ability to utilize an electronic device to perform quick and accurate calculations would benefit the user by reducing their dependence upon number of separate products including, for example, various medical instruments, tables, books and charts, pieces of diagnostic equipment, stethoscopes, height/weight scales, writing pens, patient charts, prescription pads, and the like. Although conventional electronic devices may be effective in calculating non-linear equations, the user must handle and operate these devices separately in addition to various other items. Many health-care providers, technicians, mechanics and other users would like to reduce the number of items that they must handle during the performance of their duties.
The present invention generally relates to a hand-held device which is capable of computing a single type of computation using a single set of input variables (which are related by their mathematical formulas and/or their interrelated technological relationships or values). For example, a physician may use such an implement to calculate the various physiological relationships for a patient, such as their Body Mass Index, Body Surface Area, Creatinine Clearance and Hemoglobin A1C to Mean Plasma Glucose Estimation and other associated measures. In the past, upon examining a patient and obtaining his or her vitals, the medical service provider would then refer to separate specific formulas and tables to compute the desired information for the patient.
While hand-held calculators may perform some of these functions, the relatively large size and lack of attachment means make them not as desirable as a portable hand-held non-linear algorithm calculating device. Moreover, previously designed calculators typically perform singular functions and do not incorporate preprogrammed mathematical formulas for the calculation of specific measures or values required in particular fields of use. Moreover, commonly known calculators cannot be secondarily used as a countdown timer or attach to a stethoscope.
The need for a calculating product incorporated in a hand held implement has been attempted in the past. U.S. Pat. No. 5,028,764 to Kuhlengel discloses a pen with rotatable cylindrical elements that is used to perform a simple calculation in the multiplication of two numbers. In this patent, the invention provides its user no capability to perform a specific calculation based upon a preprogrammed known scientific formula, as the pen will not permit a calculation other than basic multiplication and relies upon the user to supply a formula. U.S. Pat. No. 4,141,073 to Tan describes a pen that may be used to perform various calculations. In that pen, signals generated by the pen tip through designated strokes of numerals and calculating symbols upon writing on any surface of any writing medium are input directly to the calculator to perform calculating and displaying functions. The Tan invention therefore is doubly complicated as it relies upon the user to know or refer to a specific formula and thereafter demands the user essentially tap out a series of carefully orchestrated movements in order to perform even the simplest calculation. Therefore, neither patent involves a device which may be employed to quickly determine the numerical outcome of a specific formula or equation, such as the Body Mass Index.
U.S. Pat. No. 6,104,603 to Wang discloses a writing pen with an integral electronic calculator including printed circuit board, keyboard and power supply. While this invention is perhaps more versatile than those of Kuhlengel and Tan, it too is nothing more than the insertion of a hand held calculator into a pen. The user must still refer to outside formulas and take care to properly input any specific variables if they wish to perform a calculation based on a specific known formula. Moreover, that device has little or no capability to handle non-linear and other unusual relationships between variables in a known scientific formula, such as those physiological factors for which different values must be used for each sex.
Therefore, there is a need for a portable hand-held electronic device that is capable of calculating a non-linear algorithm, includes a countdown timer, and an attachment means for retaining the device against an external object, such as a stethoscope.